S. Mohajer - Institute of Biological Sciences, Faculty of Science, University of Malaya, ۵۰۶۰۳ Kuala Lumpur, Malaysia.
R. M. Taha - Institute of Biological Sciences, Faculty of Science, University of Malaya, ۵۰۶۰۳ Kuala Lumpur, Malaysia.

Genus Onobrychis is an important forage crop consisting of approximately ۱۳۰ annual and perennial species. The present research focused on the cytological studies of Embryogenic (E) and Non-Embryogenic (NE) callus as well as root meristem cells of in vitro and in vivo grown plants. On the contrary to the previous studies, a diploid viciifolia variety with ۲n= ۲x= ۱۶ chromosomes was observed for the first time in Onobrychis viciifolia ScopSyn. Onobrychis sativa L. Mitotic division was in general regular for all the growth conditions, but some such division irregularities as cytomixis, binucleate cells, micronucleus, asynchronous nucleus and chromosome bridge were also observed particularly in non-embryogenic callus samples. Ratio of nuclear to cell area of callus was slightly less than those in in vivo and in vitro values. Polyploidy level of DNA (C-value) was only indicated in callus. G۱ had the highest percentage of nucleus among different stages of the interphase in in vitro and in vivo growth cultures. Karyotypic formula was ۱۰ m+۶ sm and a secondary constriction was distinguished in the short arm of the second pair chromosomes. Ultimately, scanning electron microscopy was employed to differentiate between root cells of the in vitro and in vivo growth systems.

Callus, Mitotic, Karyotype, Onobrychis viciifolia, Polyploidy